Development of a Broadband Terahertz WR-3 Waveguide Microcalorimeter in the 220~330 GHz

This article proposes a power sensor and a WR-3 waveguide microcalorimeter that can achieve traceable measurement of 220 ⁓ 330 -GHz terahertz wave power. The power sensor is based on a novel multilayer sensing chip with a smaller size and easier chip connection. The energy absorption of the terahertz power sensor could be more than 90%. The proposed WR-3 rectangular waveguide microcalorimeter has measurement stability and thermopile linearity. Subsequently, the measurement results of the proposed microcalorimeter are calibrated with mathematical derivation and practical experiments. It demonstrates that the proposed microcalorimeter could work well with an effective efficiency measurement uncertainty of 0.017⁓ 0.035 ( k =2 ) in the band of 220 ⁓ 330 GHz.